Step 1:
In descriptive statistics, a box plot or boxplot (also known as box and whisker plot) is a type of chart often used in explanatory data analysis. Box plots visually show the distribution of numerical data and skewness through displaying the data quartiles (or percentiles) and averages.
Step 2:
To sketch a boxplot, you will need to determine the following:
Minimum
Lower quartile
Median
Upper quartile
Maximum
Step 3:
USA
First arrange the data from the least to the greatest.
14 , 26, 33, 34, 35, 38, 40, 41, 44, 46, 46, 49, 53, 66, 70.
Minimum = 14
[tex]\begin{gathered} \text{Lower quartile position = }\frac{1}{4}(n+1)^{th} \\ \text{= }\frac{15+1}{4}\text{ = }\frac{16}{4}=4^{th} \\ Q_1\text{ = lower quartile = 34} \end{gathered}[/tex]
Median = 41
[tex]\begin{gathered} \text{Upper quartile position = }\frac{3}{4}(n+1)^{th} \\ =\text{ }\frac{3\text{ }\times(15+1)}{4} \\ =12^{th} \\ Q_3\text{ = upper quartile = 49} \end{gathered}[/tex]
Maximum = 70
Interquartile range IQR = 49 - 34 = 15
Canada
22, 28, 31, 31, 35, 35, 36, 39, 40, 40, 42, 49, 53, 63, 68
Minimum = 22
[tex]\begin{gathered} Q1\text{ Position = }\frac{(n+1)^{th}\text{ }}{4}\text{ = }\frac{16}{4}th=4^{th} \\ Q_1\text{ = 31} \end{gathered}[/tex]
Median = 39
[tex]\begin{gathered} UpperquartileQ_{_3\text{ }}\text{ = 49} \\ \end{gathered}[/tex]
Maximum = 68
Interquartile range = 49 - 31 = 18